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Updated: Feb 16, 2026
Preparation of Carbon Nanosheets at Room Temperature
Published on: March 8, 2016
High-Density Modification of H-Terminated Si(111) Surfaces Using Short-Chain Alkynes
Sidharam P Pujari1, Alexei D Filippov1, Satesh Gangarapu1
1Laboratory of Organic Chemistry, Wageningen University , Stippeneng 4, 6708 WE Wageningen, The Netherlands.
Abstract:
H-Si(111)-terminated surfaces were alkenylated via two routes: through a novel one-step gas-phase hydrosilylation reaction with short alkynes (C3 to C6) and for comparison via a two-step chlorination and Grignard alkenylation process. All modified surfaces were characterized by static water contact angles and X-ray photoelectron spectroscopy (XPS). Propenyl- and butenyl-coated Si(111) surfaces display a significantly higher packing density than conventional C10-C18 alkyne-derived monolayers, showing the potential of this approach. In addition, propyne chemisorption proceeds via either of two approaches: the standard hydrosilylation at the terminal carbon (lin) at temperatures above 90 °C and an unprecedented reaction at the second carbon (iso) at temperatures below 90 °C. Molecular modeling revealed that the packing energy of a monolayer bonded at the second carbon is significantly more favorable, which drives iso-attachment, with a dense packing of surface-bound iso-propenyl chains at 40% surface coverage, in line with the experiments at <90 °C. The highest density monolayers are obtained at 130 °C and show a linear attachment of 1-propenyl chains with 92% surface coverage.
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Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
02:47Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
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02:38Electrophilic Addition to Alkynes: Halogenation
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02:37Structure and Physical Properties of Alkynes
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